<span>7x+6y=30
6y = -7x + 30
y = -7/6x + 5
answer:
slope = -7/6</span>
To answer this question you have to create a system of equations. The first equation will be that Devi's money (x) equals her brother's money (y), or x = y. The next equation would be that (3/5)x + (7/10)y = 78. You than can substitute x in for y because x = y. The equation would know be (3/5)x + (7/10)x = 78. You then combine the like terms to create an equation of (13/10)x = 78. Then, multiply both sides by 10 / 13 in order to isolate x. This will create the equation x = 60. This means that Devi and her brother each had 60 dollars. You then find out how much they spent and add it together. You can do so with the equation (2/5)x + (3/10)y = z, with z being total money spent. You substitute 60 in for x and for y then solve. When you solve you see that 24 + 18 = z, or that z equals 42. In other words, they spent 42 dollars altogether.
If a line's slope is

, the slope of the perpendicular line is

in this case, the given line has a slope 4, which is 4/1, so the perpendicular line has a slope/gradient
Answer: 25%
Step-by-step explanation: The question tells us that the population decreases by 1/4 every single year. That means, since 1/4 equals .25, the population decreases by 25% every year :)
B. natasha,because what is 27-11? 16 and which one is higher 11 (stephen) or 16(natasha) hope this helps! :)